Studies on Ag/Polypyrrole composite deposited on the surface of styrene-methyl acrylate copolymer microparticles and their electrical and electrochemical properties

The colloidal dispersion of silver nano particles with different concentration (0.5, 1.0 and 1.5%) were synthesized by chemical reduction method using citrate as reducing agent. Colloidal dispersion of Poly (Styrene-co-methylacrylate) (SMA) was synthesized by mini emulsion polymerization technique. The SMA micro particles were used as template for the polymerization of pyrrole in presence of dispersion of silver nano particles by oxidative coupling method. The Ag nano particles and the final core-shell composite particles were characterized by UV-visible, FTIR, SEM, EDX and TEM analysis. The thermal analysis revealed that the SMA-PPy-Ag core-shell particles possesses better thermal stability in comparision with bare PPy-Ag nano composite. The dc conductivity and the electro chemical behaviour of the particles were studied by using a standard four-probe method. The dependence of electrical conductivity of the composites on the concentration of silver in the polypyrrole shell and the methyl acrylate content in SMA copolymer were also investigated The core-shell particles show reversible electrochemical response as revealed by the cyclic voltammetry study.